These teachings relate generally to flexible substrates that can be used in tunable electronics applications.
Printed electronics for RF and microwave applications is a very promising technology due to advantages such as rapid prototyping, low temperature processing, and low cost. The ability to print on flexible thin substrates for RF and Microwave applications such as filters, transistors, antennas, and Frequency Selective Surfaces (FSS) has been exploited.
Recently, with the rapid development of printed electronics industry, there is a growing demand for desirable substrates with unique performance requirements such as high dielectric constant and low loss tangent as well as low cost and easy processability. Flexible, light weight substrates play a vital role in the development of new-form-factor RF applications, and functionalized flexible substrates can be developed to obtain specific properties, not readily found in commercial substrates.
Due to the ease of processing and great compatibility with printed electronics, there has been growing interest in ceramic-polymer composites because they are able to satisfy key requirements such as the aforementioned desirable electromagnetic properties, as well as suitable mechanical flexibility and processing possibilities.
Ferroelectric perovskite oxides are multifunctional materials which are sensitive to temperature, mechanical forces, and external electrical fields, especially near the phase transition temperature. Therefore, ferroelectric perovskite oxides can be used in a wide number of electronics applications, such as RF and Microwave applications. Moreover, the dielectric constant of some Ferroelectric perovskite oxides can be modified when a bias voltage is applied. This tunability feature in multi-phase BST-polymer composites utilized had been previously exploited in phase shifters for conformal antennas [3] and in developing fully printed varactors and phase shifters.
There is a need for flexible substrates that can be used in tunable electronics applications.